1. Field of the Invention
The present invention relates to the art of electrical connectors, and more particularly to a land grid array connector assembly having a securing mechanism for securing a land grid array (LGA) package therein.
2. Description of the Prior Art
A land grid array (LGA) connector is commonly used in the electronic transmission field for accommodating an LGA package therein, and establishing electrical connection between the LGA package and a substrate such as a printed circuit board (PCB) on which the connector is mounted). U.S. Pat. Nos. 5,344,334, 5,302,853, 4,682,790, 4,621,884, and 4,504,105 disclose several conventional LGA sockets. As can be seen from FIGS. 8 and 9, one kind of conventional LGA connector assembly 9 typically includes a low profile insulative housing 91 and a securing mechanism attached to the housing 91. The securing mechanism comprises a frame 92, a pressing plate 93 pivotally attached to one end beam of the frame 92 for pressing and securing the housing 91 in the frame 92, and a lever 94 movably connected to an opposite end beam of the frame 92 for generating a downward pressing force to press the pressing plate 93 toward the housing 91.
The lever 94 comprises an operation handle 942 located corresponding to a lateral beam of the frame 92, a locating portion 941 perpendicularly connecting with the handle 942, and an offset camshaft 943 integrally bending from a middle portion of the locating portion 941. The camshaft 943 is adapted to engage with a hook 931 formed at a free end of the pressing plate 93. The handle 942 can rotate relative to the frame 92 between a 0-degree-angle position in which the pressing plate 93 is at an open state with the hook 931 being free from the camshaft 943, and a 180-degree-angle position where the pressing plate 93 is at a closed state with the hook 931 being pressed and located by the camshaft 943. A pair of spaced locating blocks 921 is formed on said opposite end beam of the frame 92. The blocks 921 define a pair of locating slots 922 therein respectively, the locating slots 922 pivotably accommodating the locating portion 941 therein. Each slot 922 spans upwardly and inwardly along the block 921 from a lowest portion of the slot 922 to a highest portion of the slot 922. Ideally, when the handle 942 is at the 0-degree-angle position, the locating portion 941 should be positioned at the lowest portions of the slots 922, so that the camshaft 943 is completely free from the hook 931. Then when the handle 942 is rotated to the 180-degree-angle position, the locating portion 941 should be moved to the highest portions of the slots 922, so that the hook 931 is fully pressed and accurately located by the camshaft 943.
However, in actual use, when the handle 942 is at the 0-degree-angle position, the locating portion 941 may be displaced from the lowest portions and instead be located at intermediate positions between the lowest and highest portions. Thus, when the handle 942 is rotated from the 0-degree-angle position toward the 180-degree-angle position, the locating portion 941 slides along the slots 922 from the intermediate position, and may reach the highest portions prior to the handle 942 reaching the 180-degree-angle position. When this happens, the locating portion 941 cannot continue any further along the slot 922 since it has reached the highest portion of the slot 922, and the handle 942 is restrained from reaching the 180-degree-angle position. As a result, the camshaft 943 fails to generate sufficient downward pressing force on the hook 931, and the pressing plate 93 cannot be pressed to its correct closed state. The housing 9 is thus liable to be inaccurately and unreliably located.
An improved land grid array connector assembly which overcomes the above-mentioned shortcomings is desired.
Accordingly, an object of the present invention is to provide a land grid array connector assembly having a securing mechanism for accurately and securely retaining an LGA package onto a connector housing of the connector assembly.
Another object of the present invention is to provide a securing mechanism attached to a land grid array connector to accurately retain an LGA package in the land grid array connector.
In order to achieve the objects set forth, a land grid array connector assembly in accordance with the present invention includes an insulative housing and a securing mechanism attached to the housing. The securing mechanism comprises a frame surrounding the housing, a pressing plate movably attached to one beam of the frame, and an actuating lever pivotally attached to another opposite beam of the frame. The frame has an opening for receiving the housing therein, the lever can rotate between an open position and a closed position relate to the frame, and can generate a downward pressing force to a hook of the plate thereby locating the housing in the opening of the frame.
The frame further comprise a pair of locating blocks formed on one beam thereof, each block defines a locating slot for receiving a locating portion of the lever. The slot extends upwardly and inwardly toward the opening of the frame thereby forming a slantwise groove which has a lowest portion and a highest portion. A tongue portion is formed on the beam of the frame beside the locating block and extends in a direction substantially the same as the extending direction of the slot. A lower surface of the tongue portion is a continuous arc surface which can generate a pushing force which is adapted to keep the locating portion of the lever at the lowest portion of the slot when the lever is at an open position. Alternatively, the lower surface of the tongue also can form two continuous arcs jointed by a projection protruded from a middle portion of the surface, which can locate the locating portion of the lever either at the lowest portion or the highest portion of the slot.